We demonstrate an ~10<sup>4</sup> increase in conversion efficiency for optical second-harmonic generation (SHG) from a periodically nanostructured metal structure consisting of a single subwavelength aperture in a thin silver film surrounded by a set of concentric surface grooves. The forward-transmitted second-harmonic radiation from this structure is measured relative to that from an identical aperture with no surrounding surface periodicity. We explain the observed SHG enhancement quantitatively in terms of a measured 120× increase in the strength of the fundamental radiation in the vicinity of the aperture resulting from the periodic nanostructuring.
© 2003 Optical Society of America
Ajay Nahata, Richard A. Linke, T. Ishi, and K. Ohashi, "Enhanced nonlinear optical conversion from a periodically nanostructured metal film," Opt. Lett. 28, 423-425 (2003)